Through ringing repeater circuits.



U. S. DEMAREST.

THROUGH RINGING REPEATER cmcuns.

APPLICATION FILED APR.I1. 191B.

Patented Nov. 11, 1919.

INVENTOR.

C 5 Dearest BY {4% I v W ATTORNEY.

lllllllllll IIIIIHHIV Qlllllll IIIIHHIIII U N I'PED STATES PATEN TOFFICE.

. CHARLES s. nnmmn'sr, or BROOKLYN, New roux, nssreivon '10 AMERICANTELE- PHONE AND TELEGRAPH cor rANY, A conronn'rron or NEW YORK. I

THROUGH RINGING- REPEATER CIRCUITS.

Specification of Letters ram.

Patented Nov. 11,1919.

.Application filed April 11,1918. Serial No. 228,006.

To all whom-it hwy concern:

Be it known that L'CHARLES S. DEMAREs'r,

residing at Brooklyn, in the county of Kings and State of New York, haveinvented certain IIn rov'ements in Through Repeater ircuits, of whichthe following is a specification.

This invention relates to transmission lines in which are includedrepeater elements, and more particularly to a means for transmittingringing current over such lines.

It is one of the objects ofthe invention to provide a means fortransmitting signaling currents, for ringing or other purposes,

about a repeater'station included in a transmission line. Another objectconsists in providing a means for associating the relaying apparatuswith the repeater arrangement so that the relaying apparatus willreceive a greater proportion of the incoming signalmg current than inprevious arrangements.

A further object consists in providing relaying apparatus which isindependent of the repeater apparatus and which is capable of beingassociated with different types of repeaters. A further object is toprovide means for preventing the repeater from singing when signalingcurrent is transmitted around it. Other and further objects-of theinvention will be clear from the detailed description to be given later.

The purposes of this invention arefaccomplished by associating withthe-trans;

mission line on eitherside of the repeater, bridges including relaymeans adapted to transmit ringing currents, but offering a high-Incoming impedance to talking currents.

ringing current-will pass throu h one of these bridges and operate there a'y means included therein. These relay means serve to close acircuit about the repeating apparatu's and operate relay meanslocated atthe other side of the repeater. These last mentioned relay means serveto open the talking circuit of therepeater and to connect the outgoingconductors of the repeater. to a source of ringing current. mentionedrelay means also serve to close a bridge including a balancing networkelement across the talking conductors of the repeater to balancetherepeater when the line is opened forringing and thusprevent singing ofthe repeater.

These last- This invention may now be more tully understood from thefollowing description taken in connectionwith theaccompanying drawing inwhich-is illustrated a preferred form of the cir'cuitarran ement of myinvention. The characters 1 and L represent incoming and outgoingtransmission lines associated with atwo-way twoelement repeater which isdiagrammatically ilustrated as including the repeater elements R and R 1Therepeater'e ements R R areherein illustrated as of themechanical type,although any other well known typga, such as the vacuum tube repeatermay e employed. Associated with the repeater elements R and R, are theartificial lines N 'and N adapted to balance-sections L and L5,respectively, of the transmission line. Bridged across thesections L andL, of the transmission line. are ,therelays 2 and 24, respectively.These relays respond to rin ing current coming'in over the sections 13,and L of the line, but offer high impedance to talking currents. Underthe control of relays 24. and 2, respectively, are

additional relays 9 and 11 which serve to connect sources 38"and 39 ofringing current to the outgoing sections ofthe line. Under the controlof'the relays 9 and 11 are bridges across the talking conductors of therepeater set' which include the balancing network elements 20 and 35.These balancing network elements serve to balance artificiallines N and-N with respect to the repeater elements R and B, when the talkingconductors of. the '.repeater set are opened for ringing purposes by therelays ,9

ing singing during the ringing operation.

.and 11, and thus pr'ovidemeans for prevent I I Further details of theinvention will now I be clear from the following description of itsoperation: Ringing current coming in over the line section L will betransmitted over the bridge including conductor 1, windings of relay'2and over conductor 3. Ringing current will energize relay 2 which pul sup its armature-and opens" the ,followin normally closed circuit: Fromground an battery, winding of relay 4,0onductor5, contact and armatureof relay 2 to ground. The opening of this circuit deenergizes the rela4. The deenergization of relay 4 allows its armature to retract andcloses the following circuit: fronrground, contact 6,

over conductor 7, contact 8, lowerfarniature ductor 15. Ringing currentwill, then be ductor 17, contact point 22, upper armature I '26 which ina manner similar 'lvh en the relay 11 is energized, as

up its lower armature and hold tact point 36 a circuit throughtransmitted through the transformer 16 and out over the section L. ofthe transmission line. If it is desiredthe transformer 16 may beeliminated and conductors 14 and- 15 may be directly connected to thesides of line L.

P?- viously pointed out, and the talking circuit .of the repeater isopened at contact points 12 and 13, the following bridge is closedacross the talking conductors 17 and 18 From eonof relay 11, conductor21, balancing network 20. conductor 19 to the conductor 18. Thebalancing network 20 has aniinpedance substantially equal to theartificial line N and accordingly prevents the repeater from singingwhfi'ringing is taking place as it maintains the balance of the repeaterwhich would normally be destroyed when the'talking and 13, \VhenJc-herelay ll is energized, as

riiviously pointed out, and ringing current' is applied to the outgoingsection L, of the transmission line the relay 11 will also pull open atcont-lie winding 'of'relay 9. By this means-any of the ringing currenttransmitted out over line L which may pass over the bridge includingrelay 2& and may operate said relay will be prevented from operating therelay 9 which would send ringing 'current back in the wrong direction.Ringing current coming in over the section L of the transmission linewill be trans mitted through the bridge, including the conductor 23,windings of relay 24 and the conductor 25 and will energize the relay-2-'i.

The rehy 24, in a manner similar to the relay 2, controls the operationof the relay to the relay 4 controls-the operation of the relay't). Theoperation of relay 9 in a manner similar to the relay ;11 will serve toconnect the source 38 of ringing current tothe conductors 30 and 31which" inturnjvill be transmitted through I the transformer 32 and outover the section L of'the transmission line. 5 At the. same time therelay 9 will close the bridge across the talking conductors 33 and {34'to the repeater which includes the"-bala ncino" network 35 which servesto maintain the ba ance of the repeater in a manner similar to thebalancing network 20 Infill-t0- prevent circuit was broken at'contactpoints. 12

singing of the repeater during'ringing. The relay 9 will in a mannersimilar to relay 11 pull up its lower armature and hold open at contact'point'8 a circuit through the winding of relay 11 and thus prevent thetransmission of I aringing signal in the wrong direction by theoperation of rela 2 bridged across the line on one side of the re--peater, relay means controlled. by saidresponsive means and associatedwith said defined in the foltransmission line on the other side of saidrepeater, a source of ringing current and means controlled by said relaymeans to connect said source ofringing current tosaid' trans missionline.

2. A transmission line including a 're-' peatei', means responsive toringing current bridged acrom said line on eitherside of said repeater,relay I said responsive-means and associated with said transmission lineon either side of said repeater, sourcesvof-ringing' current aind'nieanscontrolled by-said relay means to (said transmission line. H

' 3. A -transmissiim line including-a' repeate neans responsive to;ringing current bridged across said line-=on either 'sidelof saidrepeater, relay me a n' s controlled by said responsive means andassociated with -connect said sources. of ringing current to saidtransmission line-on either side of said.

means controlled by repeater, sources of ringing current, meanscontrolled bysaid'i'elay means to'connect said sources of ringingcurrent to said transmission line, and means, operating when the relaymeans at one side of therepeater is ac-' tuated to prevent the actuationof'tlie-relay means at the other side of the repeater.

4. A transmission line including a 1'15 peater, means responsivetoringing current bridged across said line on either side ofsaidrepeater, relay means controlled said responsive means andassociated the said transmission line on either-side of said repeater,sourcespf ringing current associated with saidrelay-nieans, and meanscontrolled by said relay means to associate said" sources of ringingcurrent to said transmission line.

. 5. In a telephone transmission line includ- 1' .ing'a repeater, relaymeans bridged across 'the transmission line'at'one side of the repeater,a normally energized relay controlled I by-said relay means, a relaycontrolled by said normally energized relay,and asource of ringingcurrent associated with said third-mentioned relay, said relaycontrolling 1the application of ringing current to the 6, In a telephonetransmission line, a repeater, artificial lines associated therewith,balancing networks located on either side of the repeater, a source ofringing current associated with either side of the,line,means responsiveto ringing current transmitted over one portion of said transmissionline to connect said source to another portion of said transmission lineand to bridge one of said balancing networks across a portion of saidtransmission line.

In a transmission line the combination of a repeater, artificial linesassociated therewith, balancing means for said repeater and artificiallines,

side of the repeater, relay means associated with the'incomlng andoutgoing sections of the line and controlled by the responsive means atthe opposite side of the repeater,

sources of ringing current for each section of the transmission line,and means controlled by said relay means to connect said sources ofringing current to sections of the transmission line and to associatethe balancing means with the portion of the transmission line connectedto the repeater.

In testimony whereof, I have signed my name to this specification thiseighth day of April, 1918.

CHARLES s. DEMAREST.

